js解构赋值

解构赋值

• 解构赋值可以同时对一组变量进行赋值

     var array = ['李雷','韩梅梅','老王'];
     //传统方式
     var a = array[0];
     var b = array[1];
     var c = array[2];
     //解构赋值
     var [d,e,f] = array;
     console.log('d = ' + d);
     console.log('e = ' + e);
     console.log('f = ' + f);

• 在解构赋值的时候，要注意嵌套层次和位置保持完全一致

    var [x,[y,z]] = ['李雷',['韩梅梅','老王']];
    console.log('x = ' + x);
    console.log('y = ' + y);
    console.log('z = ' + z);

• 只对一个变量赋值

	var [,,o] = array;
	console.log('o = ' + o);

• 从对象中取出若干属性，可以使用解构赋值

    var person = {
        name: '元芳',
        age: 20,
        sex: '不明',
        school: '狄仁杰大学',
        address:{
            city: '王者荣耀峡谷',
            phone: [phone]
        }
    };

    var {name,age,sex,school} = person;
    console.log('name = ' + name);
    console.log('age = ' + age);
    console.log('sex = ' + sex);
    console.log('school = ' + school);

    var {name:username,address:{city,phone}} = person;
    console.log('name = ' + username);
    console.log('city = ' + city);
    console.log('phone = ' + phone);

• 交换两个数的值

    var x = 5, y = 6;
    [x,y] = [y,x];
    console.log('x = ' + x);
    console.log('y = ' + y);